Competitive interaction between two leaf morph populations of white clover in relation to soil nitrogen

Summary The pure and mixed stands of the two populations of white clover (Trifolium repens L.) differing in leaf character were raised in the experimental pots using de Wits' replacement series. Of the two populations, one is characterized by having white V-shaped markings on the leaflets (marked population) and the other does not have any such marking (unmarked population). The competitive interaction between the two populations has been studied at two soil nitrogen regimes. The nitrogen requirement of the marked population seems to be higher than that of the unmarked population. The marked population was found to be more competitive as compared to the other population at high N level as shown by their relative yield. The competitiveness of the former was, however, masked to some extent under low soil nitrogen. This confirmed the differential response of the two populations ofT. repens to soil fertility as observed in nature.